Highly ordered and NiO nanocolumns have been successfully achieved by glancing-angle deposition (GLAD) using an electron beam evaporator. Nanocolumnar and NiO sensors exhibited high performance owing to the porous nanostructural effect with the formation of a double Schottky junction and high surface-to-volume ratios. When all gas sensors were exposed to various gases such as , , and , the response of the highly ordered nanocolumn were over 50 times higher than that of the thin film. This work will bring broad interest and create a strong impact in many different fields owing to its particularly simple and reliable fabrication process.